Attitudes towards Zika screening and vaccination acceptability among pregnant women in Malaysia

Influence of maternal risk perception and vaccination knowledge on childhood vaccination intentions

BACKGROUND

Vaccine hesitancy remains a significant barrier to effective public health strategies aimed at overcoming the resurgence of vaccine-preventable diseases globally. This study aims to explore the roles of maternal knowledge, risk perception, health self-efficacy, and demographic characteristics in influencing the intention of antenatal mothers to accept childhood vaccination for their newborns.

METHODS

A descriptive and analytic cross sectional study design was conducted from March to September 2021, among antenatal mothers attending routine antenatal follow-ups at 17 public health clinics in Selangor, Malaysia. A validated and reliable self administered questionnaire was used to collect data on demographic characteristics, knowledge, risk perceptions, health self-efficacy, and vaccination intentions among antenatal mothers. Multiple linear regression analysis was used to identify determinants of vaccination intention among antenatal mothers.

RESULTS

The study included 796 antenatal mothers, predominantly Malay mothers (87.5%). The respondents presented a high mean vaccination intention score of 26.02 ± 2.77. Significant determinants of vaccination intention among antenatal mothers included the number of children (β = 0.156, 95% CI [0.013, 0.299], p = 0.032), knowledge score (β = 0.397, 95% CI [0.288, 0.506], p < 0.001), and risk perception score (β = 0.047, 95% CI [0.036, 0.058], p < 0.001). However, health self-efficacy was not significantly associated with vaccination intention.

CONCLUSION

Psychological and cognitive factors play important roles in influencing maternal vaccination intention. Intervention that aimed at increasing level of maternal knowledge and addressing maternal risk perception, focusing on less experienced mothers would be an effective strategies to improve maternal vaccination intention.

Health Systems Determinants of Delivery and Uptake of Maternal Vaccines in Low- and Middle-Income Countries: A Qualitative Systematic Review

Maternal vaccination is considered a key component of the antenatal care package for improving maternal and child health. Low- and middle-income countries (LMICs) fall short of global targets to prevent maternal and neonatal deaths, with a disproportionate burden of vaccine-preventable diseases. Strategies towards ending preventable maternal mortality necessitate a health systems approach to adequately respond to this burden. This review explores the health systems determinants of delivery and uptake of essential maternal vaccines in LMICs. We conducted a qualitative systematic review of articles on maternal vaccination in LMICs, published between 2009 and 2023 in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Thematic analysis was conducted to identify key themes in the literature, interpreted within a conceptual framing that explores the systems determinants influencing maternal vaccines. Our search yielded 1309 records, of which 54 were included, covering 34 LMICs. Most of the included studies were from South America (28/54) and included pregnant women as the primary study population (34/54). The studies explored influenza (25/54) and tetanus toxoid (20/54) vaccines predominantly. The findings suggest that systems hardware (lack of clear policy guidelines, ineffective cold-chain management, limited reporting and monitoring systems) are barriers to vaccine delivery. Systems software (healthcare provider recommendations, increased trust, higher levels of maternal education) are enablers to maternal vaccine uptake. Findings show that formulation, dissemination and communication of context-specific policies and guidelines on maternal vaccines should be a priority for decision-makers in LMICs.

Acceptability of a Chikungunya Virus Vaccine, United States Virgin Islands

Chikungunya virus, a mosquito-borne alphavirus, causes acute febrile illness with polyarthralgia. Groups at risk for severe disease include neonates, people with underlying medical conditions, and those aged ≥ 65 years. Several chikungunya vaccines are in late clinical development with licensure expected in the United States during 2023. We administered a questionnaire to randomly selected households in the U.S. Virgin Islands (USVI) to assess interest in a hypothetical chikungunya vaccine. Estimates were calibrated to age and sex of USVI population, and univariate and multivariable analyses were performed. Of 966 participants, 520 (adjusted 56%, 95% CI = 51-60%) were interested in receiving the vaccine. Of 446 participants not interested in vaccination, 203 (adjusted 47%, 95% CI = 41-52%) cited safety concerns as the reason. Educational efforts addressing vaccine safety concerns and risk factors for severe disease would likely improve vaccine acceptability and uptake among those most at risk.

Models of determinants of COVID-19 vaccine hesitancy in non-pregnant and pregnant population: Review of current literature"

Vaccination has proven to be the most effective tool in controlling the COVID-19 pandemic. While pregnant individuals are considered to be a high-risk population and are more likely to experience adverse effects from COVID-19, vaccination rates among pregnant individuals are significantly lower than in the general population. The Health Belief Model (HBM), Theory of Planned Behavior (TPB), 3C model, 5C model, and 5A model have been used to assess vaccination hesitancy behaviors. In this paper, we review the use of each of these models to address vaccine hesitancy, with a focus on the pregnant population and the COVID-19 vaccine. The HBM, TPB, 3C model, and 5C model have demonstrated great versatility in their ability to evaluate, explain, and modify vaccine hesitancy and behavior. Up to date, the HBM and 3C models appear to be the most effective models to study and address vaccination hesitancy within the pregnant persons.

Understanding Barriers and Facilitators to Maternal Immunization: A Systematic Narrative Synthesis of the Published Literature

Introduction

Vaccines are being developed against Group B Streptococcus and respiratory syncytial virus. These vaccines are designed to be given to pregnant women to protect infants; thus, their success depends on uptake in this population. Maternal immunization programs have struggled to achieve target coverage rates. This systematic narrative synthesis aims to define the most important barriers and facilitators for maternal immunization and to identify priority areas for future research.

Methods

A search strategy was developed in Medline and adapted according to the requirements of additional search engines. Two reviewers independently reviewed the studies, using pre-specified inclusion and exclusion criteria. Results sections of included studies were coded, and thematic analysis was used to identify prominent themes.

Results

321 studies were included in the final review. Most studies came from North America (37%), Europe (26%) or East Asia, Australia and New Zealand (22%). Low-and middle-income countries were under-represented. Five percent of studies came from Sub-Saharan Africa, and 2% came from South Asia. The prominent factors impacting maternal immunization were provider recommendation, perceived risks and benefits of maternal vaccines for the infant, race, birthplace, and access to healthcare. Few studies explored reasons behind racial and socioeconomic disparities in maternal immunization rates.

Discussion

A strong provider recommendation, equitable access to prenatal care and messaging that focuses on vaccine safety and infant benefits emerged as the key components for optimising vaccine uptake among pregnant women. Research among healthcare providers, minority groups and in low- and-middle-income countries was lacking. In anticipation of the expansion of maternal immunization programmes, focused research is needed to address these gaps and inform a successful public health strategy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10995-022-03508-0.

Health Belief Model Perspective on the Control of COVID-19 Vaccine Hesitancy and the Promotion of Vaccination in China: Web-Based Cross-sectional Study

Background

The control of vaccine hesitancy and the promotion of vaccination are key protective measures against COVID-19.

Objective

This study assesses the prevalence of vaccine hesitancy and the vaccination rate and examines the association between factors of the health belief model (HBM) and vaccination.

Methods

A convenience sample of 2531 valid participants from 31 provinces and autonomous regions of mainland China were enrolled in this online survey study from January 1 to 24, 2021. Multivariable logistic regression was used to identify the associations of the vaccination rate and HBM factors with the prevalence of vaccine hesitancy after other covariates were controlled.

Results

The prevalence of vaccine hesitancy was 44.3% (95% CI 42.3%-46.2%), and the vaccination rate was 10.4% (9.2%-11.6%). The factors that directly promoted vaccination behavior were a lack of vaccine hesitancy (odds ratio [OR] 7.75, 95% CI 5.03-11.93), agreement with recommendations from friends or family for vaccination (OR 3.11, 95% CI 1.75-5.52), and absence of perceived barriers to COVID-19 vaccination (OR 0.51, 95% CI 0.35-0.75). The factors that were directly associated with a higher vaccine hesitancy rate were a high level of perceived barriers (OR 1.63, 95% CI 1.36-1.95) and perceived benefits (OR 0.51, 95% CI 0.32-0.79). A mediating effect of self-efficacy, influenced by perceived barriers (standardized structure coefficient [SSC]=−0.71, P<.001), perceived benefits (SSC=0.58, P<.001), agreement with recommendations from authorities (SSC=0.27, P<.001), and agreement with recommendations from friends or family (SSC=0.31, P<.001), was negatively associated with vaccination (SSC=−0.45, P<.001) via vaccine hesitancy (SSC=−0.32, P<.001).

Conclusions

It may be possible to increase the vaccination rate by reducing vaccine hesitancy and perceived barriers to vaccination and by encouraging volunteers to advocate for vaccination to their friends and family members. It is also important to reduce vaccine hesitancy by enhancing self-efficacy for vaccination, due to its crucial mediating function.

Using immunisation caregiver journey interviews to understand and optimise vaccination uptake: lessons from Sierra Leone

Quantitative and qualitative assessments have revealed diverse factors that influence the uptake of childhood immunisation services and shed light on reasons for vaccination delays and refusals. UNICEF and partner organisations developed the Immunisation Caregiver Journey Framework as a novel way to understand caregiver experiences in accessing and receiving immunisation services for children. This framework aims to help immunisation programmes identify vaccination barriers and opportunities to improve vaccination uptake by enhancing the overall caregiver journey in a systems-focused manner, using human-centred design principles. In this paper, we adapt the framework into a flexible qualitative inquiry approach with theoretical guidance from interpretative phenomenology. We draw from the implementation experiences in Sierra Leone to inform methodological guidance on how to design and implement the Immunisation Caregiver Journey Interviews (ICJI) to understand the lived experiences of caregivers as they navigate immunisation services for their children. Practical guidance is provided on sampling techniques, conducting interviews, data management, data analysis and the use of data to inform programmatic actions. When properly implemented, the ICJI approach generates a rich qualitative understanding of how caregivers navigate household and community dynamics, as well as primary healthcare delivery systems. We argue that understanding and improving the caregiver journey will enhance essential immunisation outcomes, such as the completion of the recommended vaccination schedule, timeliness of vaccination visits and reduction in dropouts between vaccine doses.

Epidemic preparedness: Prenatal Zika virus screening during the next epidemic

Zika virus (ZIKV) is a vectorborne infectious agent of global public health significance due to its potential to cause severe teratogenic outcomes. The question of whether health systems should consider adopting screening programmes for ZIKV infections during pregnancy warrants consideration. In this analysis, we apply the Wilson-Jungner framework to appraise the potential utility of a prenatal ZIKV screening programme, outline potential screening strategies within the case-finding pathway, and consider other epidemiological factors that may influence the planning of such a screening programme. Our evaluation of a potential prenatal ZIKV screening programme highlights factors affirming its usefulness, including the importance of Congenital Zika Syndrome as a public health problem and the existence of analogous congenital prenatal screening programmes for STORCH agents (syphilis, toxoplasmosis, others (eg, human immunodeficiency virus, varicella-zoster virus, parvovirus B19), rubella, cytomegalovirus, and herpes simplex virus). However, our assessment also reveals key barriers to implementation, such as the need for more accurate diagnostic tests, effective antiviral treatments, increased social service capacity, and surveillance. Given that the reemergence of ZIKV is likely, we provide a guiding framework for policymakers and public health leaders that can be further elaborated and adapted to different contexts in order to reduce the burden of adverse ZIKV-related birth outcomes during future outbreaks.

Knowledge and Determinants of Behavioral Responses to the Pandemic of COVID-19

Background: Understanding knowledge and behavioral responses to the pandemic of coronavirus disease 2019 (COVID-19) is important for appropriate public health interventions.

Objectives: To assess knowledge of COVID-19 and to examine determinants associated with the adoption of preventive health behaviors among future health care providers.

Methods: An anonymous online survey was sent out to pharmacy students in high and low-endemic areas of COVID-19 in China. Based on recommendations from the Chinese Center for Disease Control and Prevention, preventive health behaviors examined in this study included washing hands, wearing a face mask, and maintaining social distancing. The Health Belief Model (HBM) was used and measured by a seven-point Likert scale (one as extremely unlikely; seven as extremely likely). Multivariate linear regression models were used to examine predictors of preventive health behaviors.

Results: Among 203 respondents who finished the survey, a medium level of knowledge (4.41 ± 0.95) of COVID-19 was reported. Respondents were extremely likely to wear a face mask (6.85 ± 0.60), but only moderately likely to engage in washing hands (5.95 ± 1.38) and maintaining social distancing (6.19 ± 1.60). Determinants of washing hands were cue to action, self-efficacy, knowledge, and gender; wearing a face mask were cue to action, self-efficacy, knowledge, and ethnicity; and maintaining social distancing were cue to action and self-efficacy.

Conclusions: Public health interventions should consider incorporating cue to action, self-efficacy, and knowledge as factors to potentially improve the adoption of face mask-wearing, hand washing, and social distancing as appropriate individual preventive measures, especially if local and regional authorities are considering reopening schools sometime in future.

Antenatal care providers' attitudes and beliefs towards maternal vaccination in Kenya

Background: Maternal immunization is known to be one of the best strategies to protect both mothers and their infants from infectious diseases. Studies have shown that healthcare providers play a critical role in implementation of maternal immunization. However, little is known about providers' attitudes and beliefs towards vaccination that can influence their vaccine recommendations, specifically in low to middle income countries (LMIC). Methods: A self-administrated knowledge, attitude and behavior (KAB) survey was provided to 150 antenatal care providers across four different regions (Nairobi, Mombasa, Marsabit, and Siaya counties) of Kenya. The research staff visited the 150 clinics and hospitals and distributed a quantitative KAB survey. Results: Nearly all of the antenatal care providers (99%) recommended tetanus maternal vaccination. Similarly, 99% of the providers agreed that they would agree to provide additional vaccinations for pregnant women and reported that they always advise their patients to get vaccinated. Between 80 and 90% of the providers reported that religious beliefs, ethnicity, cultural background and political leaders do not affect their attitude or beliefs towards recommending vaccines. Conclusions: Considering the positive responses of healthcare providers towards vaccine acceptance and recommendation, these results highlight an opportunity to work in partnership with these providers to improve coverage of maternal vaccination and to introduce additional vaccines (such as influenza). In order to achieve this, logistical barriers that have affected the coverage of the currently recommended vaccines, should be addressed as part of this partnership.

Knowledge, attitudes, and practices associated with pertussis vaccination during pregnancy: Japan, 2016-2017

Neonatal pertussis has the potential for severe complications, even death. Mothers have been identified as the most frequent source of neonatal pertussis. Almost a dozen countries have implemented pertussis vaccination programs for pregnant women to protect neonates, but Japan has not yet done so. The aim of this questionnaire-based study was to ascertain the willingness of women to be vaccinated during pregnancy and the factors associated with willingness. Subjects were 977 pregnant women who visited either of two selected hospitals for maternity health checks. Most of the women were in their first pregnancy (96%) and about half considered a physician to be the most reliable source of information about vaccination (481/977, 49%). "Willingness to receive pertussis vaccination" was significantly associated with the factors "no fear of receiving vaccination" (odds ratio [OR]=3.10, 95% confidence interval [CI]: 2.21-4.34), "necessary to prevent pertussis" (OR=8.70, 95% CI: 6.17-12.28), "effective in pregnancy"(OR=5.46, 95% CI: 3.94-7.56), and "no concern about side effects after vaccination"(OR=3.03, 95% CI: 1.66-5.55). Pregnant women are likely to consider vaccination if they have a good understanding of the disease and its outcomes. Physicians are well positioned to improve knowledge and attitudes toward pertussis vaccination during pregnancy.

Pregnant women's perceptions of risks and benefits when considering participation in vaccine trials

INTRODUCTION

Despite historical exclusion, there has been recent recognition of the need to address the health of pregnant women in research on vaccines against emerging pathogens. However, pregnant women's views and decision-making processes about vaccine research participation during infectious disease outbreaks remain underexplored. This study aims to examine women's decision-making processes around vaccine research participation during infectious disease outbreaks.

METHODS

We conducted qualitative semi-structured in-depth interviews with pregnant and recently pregnant women (n = 13), eliciting their views on four hypothetical Zika Virus vaccine research scenarios and probing their decision-making processes around participation. After recorded interviews were transcribed, thematic analysis was conducted based on a priori and emergent themes.

RESULTS

Most women interviewed were accepting of vaccine research scenarios. Three broad themes-evidence, risk, and trust-characterized women's decision-making processes. Women varied in how different types and levels of evidence impacted their considerations, which risks were most salient to their decision-making processes, and from whom they trusted recommendations about vaccine research participation. Exemplary quotes from each theme are presented, and lessons for vaccine development during the current COVID-19 pandemic and future outbreaks are discussed.

CONCLUSION

Some pregnant women are accepting of participation in vaccine research during infectious disease outbreaks. Incorporating their priorities into trial design may facilitate their participation and generation of evidence for this important population.

Acceptability of a Hypothetical Zika Vaccine among Women from Colombia and Spain Exposed to ZIKV: A Qualitative Study

Zika virus (ZIKV) can cause pregnancy loss and congenital Zika syndrome, among other poor health outcomes. The ZIKV epidemic in 2015-2017 disproportionately affected pregnant women in poor-resource settings. We aimed to understand perceptions and attitudes towards a hypothetical ZIKV vaccine, women's willingness to be vaccinated, and potential barriers and facilitators for vaccine acceptance in 1) migrant women living in Spain who travelled to their countries of origin and were diagnosed with ZIKV infection during pregnancy, and their healthcare providers, and 2) women living in Colombia who delivered a child with microcephaly. An exploratory qualitative study based on phenomenology and grounded theory was conducted. Data were collected through in-depth, paired and semi-structured interviews. Overall, women from both sites were willing to receive a hypothetical ZIKV vaccine. However, some expressed concerns of being vaccinated during pregnancy, yet they would accept it if the vaccine was recommended by a healthcare professional they trust. Main fears towards vaccination were related to vaccine safety and potential adverse effects on child's health. Women reported feeling hesitant to participate in a ZIKV vaccine trial. These results may contribute to guiding the effective delivery of future ZIKV vaccines among populations most at risk and particularly vulnerable.

Antenatal care providers' attitudes and beliefs towards maternal vaccination in Kenya

Background: Maternal immunization is known to be one of the best strategies to protect both mothers and their infants from infectious diseases. Studies have shown that healthcare providers play a critical role in implementation of maternal immunization. However, little is known about providers' attitudes and beliefs towards vaccination that can influence their vaccine recommendations, specifically in low to middle income countries (LMIC). Methods: A self-administrated knowledge, attitude and behavior (KAB) survey was provided to 150 antenatal care providers across four different regions (Nairobi, Mombasa, Marsabit, and Siaya counties) of Kenya. The research staff visited the 150 clinics and hospitals and distributed a quantitative KAB survey. Results: Nearly all of the antenatal care providers (99%) recommended tetanus maternal vaccination. Similarly, 99% of the providers agreed that they would agree to provide additional vaccinations for pregnant women and reported that they always advise their patients to get vaccinated. Between 80 and 90% of the providers reported that religious beliefs, ethnicity, cultural background and political leaders do not affect their attitude or beliefs towards recommending vaccines. Conclusions: Considering the positive responses of healthcare providers towards vaccine acceptance and recommendation, these results highlight an opportunity to work in partnership with these providers to improve coverage of maternal vaccination and to introduce additional vaccines (such as influenza). In order to achieve this, logistical barriers that have affected the coverage of the currently recommended vaccines, should be addressed as part of this partnership.

Knowledge and attitude towards pregnancy-related issues of Zika virus infection among general practitioners in Indonesia

Background

The aim of this study was to assess the knowledge and attitudes towards pregnancy-related issues of Zika virus (ZIKV) infection among general practitioners (GPs), a frontline healthcare worker group, in Indonesia.

Methods

A cross-sectional, online survey assessing knowledge and attitudes towards ZIKV infection on multiple-item scales was sent to GPs in the Sumatra and Java islands of Indonesia. The associations between independent factors and either knowledge or attitude were assessed with logistic regressions. The correlation and association between knowledge and attitude were estimated.

Results

We included 457 (53.7%) out of 850 responses in the analysis. Among these, 304 (66.5%) and 111 (24.2%) respondents had a good knowledge and attitude, respectively. No demographic, workplace, professional development, or experiential characteristics related to ZIKV infection were associated with knowledge. In the multivariate analysis, only contact experience was associated with attitude. There was a significant, positive correlation between knowledge and attitude scores.

Conclusions

Although knowledge of pregnancy-related complications of ZIKV infection is relatively high among GPs in Indonesia, more than 75% of them had a poor attitude towards pregnancy-related issues of Zika. Strategies for enhancing the capacity of GPs to develop positive attitudes and respond to ZIKV infection are needed.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4297-4) contains supplementary material, which is available to authorized users.

Zika Outbreak Emergency Preparedness and Response of Malaysian Private Healthcare Professionals: Are They Ready?

Zika virus has been declared as a public health emergency of international concern. The Center for Disease Control and Prevention has issued guidelines reminding healthcare workers about the importance of taking steps to prevent the spread of Zika virus, how to test and isolate patients suspected of carrying the Zika virus, and how to protect themselves from infection. Therefore, it is of utmost importance for healthcare professionals to be fully aware of Zika virus preparedness, and response measures should an outbreak occur in Malaysia in order to quickly and efficiently contain the outbreak, ensure the safety of individual or healthcare personnel safety, as well as to prevent further spreading of the disease. This research aims to show how prepared Malaysian healthcare professionals are against Zika virus and how well can they respond during an outbreak. In total, 504 healthcare professionals (128 general practitioners, 215 community pharmacists, 161 nurses) from private health clinics were the target population of the four states of Malaysia where Zika cases suspected. The sample size of each category was calculated by using a formula for estimating the population proportion. An additional 10% of the calculated sample size was added to compensate the non-response rate. The Center For Disease Control and Prevention and World Health Organisation provided a checklist to assess how prepared healthcare professionals are for an Zika outbreak. This checklist was modified to a questionnaire in order to assess health care professionals’ preparedness and response to the Zika outbreak. Community pharmacists are still lacking in their preparedness and perceived response to the Zika outbreak compared to the general practitioners in the private sector. Hence community pharmacists should attend training given by the Ministry of Health Malaysia as a continuing education, which may help them to respond during a Zika outbreak.

Community acceptance and willingness-to-pay for a hypothetical Zika vaccine: A cross-sectional study in Indonesia

BACKGROUND

Understanding people's perceptions of the economic benefits of a potential Zika vaccine (ZV) is critical to accelerating its introduction into either public sector programs or private market. The aim of this study was to assess the acceptance and willingness-to-pay (WTP) for a hypothetical ZV and the associated explanatory variables in Indonesia.

METHODS

We conducted a health facility-based cross-sectional study in Aceh and West Sumatra province from 1 February to 13 June 2018. Patients who visited outpatient departments, have had children or were expecting their first child, were approached and interviewed to collect information on acceptance, WTP, demographic and socio-economic variables and attitudes towards childhood vaccines. Associations of explanatory variables influencing acceptance and WTP were assessed using logistic regression and linear regression analysis, respectively.

RESULTS

In total, 956 respondents were included in the final analysis of acceptance, of whom 338 (35.3%) expressed their WTP. We found that 757 (79.1%) of the respondents were likely to be vaccinated and to recommend their partner to be vaccinated. Higher educational attainment, having a job, having heard about Zika and a good attitude towards childhood vaccination were associated with ZV acceptance in the univariate analyses. In the multivariate analysis, attitude towards childhood vaccination was the strongest predictor for ZV vaccination. We found the geometric mean and median of WTP was US$ 13.1 (95% CI: 11.37-15.09) and US$ 7.0 (95% CI: 4.47-10.98), respectively. In the final model, having heard about Zika, having a job, and higher income were associated with a higher WTP.

CONCLUSION

Although the acceptance rate of the ZV is relatively high in Indonesia, less than 40% of respondents are willing to pay, underscoring the need for a low-cost, high-quality vaccine and public sector subsidies for Zika vaccinations in the country.

Consumer willingness to pay for a hypothetical Zika vaccine in Brazil and the implications

ABSTRACT  Background: Zika virus is a newly emerging infection, associated with increasingly large outbreaks especially in tropical countries such as Brazil. A future Zika vaccine can contribute to decreasing the number of cases and associated complications. Information about consumers' willingness to pay (WTP) for a hypothetical Zika vaccine can help price setting discussions in the future in Brazil, starting with the private market.

METHODS

A cross-sectional study conducted among residents of Minas Gerais, Brazil, regarding their WTP for a hypothetical Zika Vaccine. The mean effective protection was 80%, with the possibility of some local and systemic side- effects.

RESULTS

517 people were interviewed. However, 28 would not be vaccinated even if the vaccine was free. Most of the resultant interviewees (489) were female (58.2%), had completed high school (49.7%), were employed (71.2%), had private health insurance (52.7%), and did not have Zika (96.9%). The median individual maximum WTP for this hypothetical Zika vaccine (one dose) was US$31.34 (BRL100.00).

CONCLUSION

Such discussions regarding WTP can contribute to decision-making about prices once a Zika vaccine becomes available in Brazil alongside other ongoing programs to control the virus.

Clinical Trials and Administration of Zika Virus Vaccine in Pregnant Women: Lessons (that Should Have Been) Learned from Excluding Immunization with the Ebola Vaccine during Pregnancy and Lactation

As evidenced from recent epidemics, both Ebola and Zika virus infection are potentially catastrophic when occurring in pregnant women. Ebola virus causes extremely high rates of mortality in both mothers and infants; Zika virus is a TORCH infection that produces a congenital malformation syndrome and pediatric neurodevelopmental abnormalities. Production of efficacious vaccines has been a public health priority for both infections. Unfortunately, during the clinical trials and subsequent deployment of a vaccine for the Ebola virus, pregnant and lactating women were, and continue to be, excluded from receiving the life-saving vaccine. The most serious consequence of Zika virus infection, congenital Zika syndrome, results from fetal infection during pregnancy. Thus, pregnant women have a major stake in the ongoing development of a vaccine for Zika virus. The exclusion of pregnant women from the development, clinical trials and administration of a potential Zika vaccine unfairly deprives them and their infants of the protection they need against this potentially catastrophic intrauterine infection. When creating policy about these issues, it is important to critically evaluate vaccine safety in pregnancy in the context of the substantial risk of infection for the pregnant woman and her fetus in the absence of immunization.

Pregnant women's attitudes toward Zika virus vaccine trial participation

INTRODUCTION

As Zika virus infection during pregnancy can cause a range of congenital anomalies, pregnant women may be a target population for vaccination in future outbreaks. Their inclusion in vaccine trials is critical to ensure safe and effective vaccines in pregnancy. Though many vaccine candidates are in development, pregnant women's willingness to participate in Zika virus vaccine research is unknown. This study aims to describe pregnant women's attitudes toward Zika virus vaccine research participation, as well as perceived barriers to and facilitators of enrollment.

METHODS

Pregnant and recently postpartum women (n = 128) attending prenatal care at Massachusetts General Hospital completed surveys querying their willingness to participate in four hypothetical Zika virus vaccine trials and their motivations for participation. Demographics, information on prior Zika virus exposure, and vaccine acceptance were collected.

RESULTS

Most women (77%) accepted participation in at least one hypothetical Zika virus vaccine trial, and women were significantly more likely to accept prospective enrollment in an inactivated vaccine trial compared to a live-attenuated vaccine trial (p-value <0.0001) or a nucleic acid-based vaccine trial (p-value <0.0444). Important motivators for participation included evidence from research with pregnant and non-pregnant people, a desire to protect the baby from Zika, perceptions of vaccine safety, and provider recommendation.

CONCLUSIONS

A majority of women in this cohort were willing to participate in a Zika virus vaccine trial while pregnant, however, differences in acceptance exist between vaccine platforms. The high value placed on evidence by participants highlights the importance of gathering and communicating pregnancy-specific data to potential research participants and their providers. Women's motivations for accepting research participation during pregnancy are important to inform the Zika virus vaccine research agenda, candidate prioritization, and trial design.

United States Travelers' Concern about Zika Infection and Willingness to Receive a Hypothetical Zika Vaccine

The ongoing Zika pandemic has affected many countries that are common travel destinations. We assessed the willingness to receive a prophylactic Zika virus (ZIKV) vaccine, currently under development, among travelers to areas with reported autochthonous ZIKV transmission. We surveyed United States (U.S.) residents aged 18–44 years who had ever heard of ZIKV and planned to travel to Florida and/or Texas (N = 420) or a U.S. territory or foreign country (N = 415) in 2017, using a nationally representative internet panel. Travelers to Florida and/or Texas reported less concern about ZIKV infection than travelers to other destinations (27% versus 36%, P = 0.01). Female sex, Hispanic ethnicity, discussing ZIKV with medical professionals, ZIKV risk perception, and self-efficacy for ZIKV prevention predicted concern about ZIKV infection in both groups. Travelers to Florida and/or Texas (43%) and other destinations (44%) were equally willing to receive a ZIKV vaccine. Hispanic ethnicity, discussing ZIKV with medical professionals, and concern about ZIKV infection predicted vaccine willingness in both groups. Likelihood of using existing ZIKV prevention methods, confidence in the U.S. government to prevent ZIKV spread, self-efficacy for ZIKV prevention, and knowledge about ZIKV symptoms further predicted vaccine willingness in travelers to other destinations. In multivariable analyses, only concern about ZIKV infection was associated with vaccine willingness in both groups (prevalence ratio [95% confidence interval]: Florida and/or Texas: 1.34 [1.06, 1.69]; other: 1.82 [1.44, 2.29]). Targeted communications can educate travelers, particularly travelers who are pregnant or may become pregnant, about ZIKV risk to generate ZIKV vaccine demand.